Push button switch with button-actuated carriage adapted to carry plurality of blades for simple and complex switching arrangements



Dec. 31, 1968 J. R. BAILEY ETAL 3,419,696 PUSH BUTTON SWITCH WITH BUTTON-ACTUATED CARRIAGE ADAPTED I TO CARRY PLURALITY OF BLADES FOR SIMPLE I I Am) COMPLEX SWITCHING ARRANGEMENTS Filed March 13, 1967 Sheet of 5 INVEMIL-DRS. JAMES R. BAILEY ROBERT J. BQKOSKY ATT' ,Ys

j gwww J. R. BAILEY E TAL 3,419,696 PUSH BUTTON SWITCH WITH BUTTON-ACTUATED CARRIAGE ADAPTED TO CARRY PLURALITY 0F BLADES FOR SIMPLE AND COMPLEX SWITCHING ARRANGEMENTS Sheet 2' Ora Filed march 13. 1967 FIG. I2

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PUSH BUTTON SWITCH WITH BUTTON-ACTUATED CARRIAGE ADAPTED TO CARRY PLURALITY 0F BLADES FOR SIMPLE GEMENTS AND COMPLEX SWITCHING ARRAN Sheet rum Iarcn 1:5. 1967 FIGL26 F|G.26u 1-16.29 FIG.29

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. INVENTORS: JAMES R-BAILEY I ROBERT J. BOKOSKY United States Patent 3,419,696 PUSH BUTTON SWITCH WITH BUTTON- ACTUATED CARRIAGE ADAPTED TO CARRY PLURALITY 0F BLADES FOR SIMPLE AND COMPLEX SWITCHING ARRANGEMENTS James R. Bailey, Chicago, and Robert J. Bokosky, Park Ridge, Ill., assignors to Switchcraft, Inc., Chicago, 111., a corporation of Illinois Filed Mar. 13, 1967, Ser. No. 622,760 18 Claims. (Cl. 200-159) ABSTRACT OF THE DISCLOSURE Compact multiple switch mechanism comprising a hollow housing, conductor strips forming stationary switch contacts supported in peripherally spaced contact seats in the housing, switch blades each comprising a medially bent electrical conductor having legs of unlike length and mounted each in position straddling the end of a corre sponding longitudinally extending blade mounting rib positioned, on a push-button frame, for axial movement, between an adjacent pair of said stationary contacts, the housing being formed with cam ribs at and along the contact strips to selectively permit and prevent switching engagement of the legs of said blades with seat mounted contacts, as the push-button frame is shifted axially within the housing, each switch blade being adapted for assembly, with its long and short legs straddling its mounting rib, in either direction whereby to constitute the resulting switch either as normally open or normally closed, the arrangement providing one or more simple and complex switches, in a single unit, depending upon the presence or absence and orientation of the blade elements on their mounting ribs.

The present invention relates in general to electrical switches, and has more particular reference to an improved push-button switch structure of unusual compactness and comprising a minimal number of identical component parts from which one or more simultaneously operable switches may be assembled in a single switch unit.

An important object of the present invention is to provide a push-button assembly of compact character, whereby several switch units may be mounted in closely adjacent relationship, as on a support panel; a further object being to provide a push-button switch unit comprising a housing, carrying one or more pairs of associated switch contacts, and a switch blade carrying frame, shiftably mounted on the housing and upon which one or more switch blade elements may be selectively assembled in position for switching cooperation, each with a pair of contact elements in the housing, in response to movement of the frame, in the housing, whereby the unit may be assembled with one or more switches of desired character therein, by the optional placement of blade and contact elements in the housing and on the frame.

A further object of the invention is to form the housing of a push-button switch with longitudinally extending peripherally spaced seats for supporting contact elements in position for engagement by a switch blade element or elements carried on a frame longitudinally movable from a retracted to a projected switching position in the housing; a still further object being to form the housing with an open and a closed end, and to employ elongated contact elements adapted for assembly in the housing seats by longitudinal movement of the elements into the housing, through its open end, the elements having circuit connecting ends adapted to project outwardly of the housing through openings in its closed end, the contact elements being provided each with a shoulder adapted to engage a seat formed, in the closed end of the housing, to retain the contact elements in mounted position therein.

Another important object of the invention is to provide a push-button switch having a housing supporting spaced, longitudinally extending contact elements, and a longi tudinally movable push-button frame providing a plurality of seat forming ribs disposed between adjacent pairs of contact elements, said ribs each carrying a switch blade element in position for switchimaking and breaking cooperation with a corresponding pair of said contact elements; a further object being to employ a medially bent switch blade element having legs straddling a said rib, to thereby present the legs in position for selective engagement respectively with a cooperative pair of contact elements on opposite sides of the blade carrying rib; a further object being to provide blade engaging cam means, on the housing, in position to ridingly engage the blade legs, to determine the engagement thereof with cooperating contact elements, as the blade is shifted longitudinally in the housing with the push-button frame.

Briefly stated, the present invention contemplates a compact push-button switch unit comprising a hollow housing open at one end and closed at the other, and a push-button frame longitudinally movable in the housing between a spring biased normally retracted position and a projected position, the housing containing one or more sets of peripherally spaced contact strips extending longitudinally therein, including at least one and preferably a pair of sets of three contact strips, and at least one and preferably a pair of sets of two contact strips, the pushbutton frame providing a mounting for a switch blade element or elements in position to cooperatively electrically engage and release the contact strips of said sets, as the frame is moved between retracted and projected position, the frame having blade carrying fingers extending between and movable longitudinally of the spaced contact strips of the strip sets and carrying switch blades loosely shackeled on said fingers, for switching cooperation between spaced pairs of contact strips, said blades comprislng medially bent conductor elements having legs straddling said carrying fingers in resilient compression each between 1ts cooperating pair of contact strips to assure switching connection between the blades and said strips.

The foregoing and numerous other important objects, advantages, and inherent functions will become apparent as the invention is more fully understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment of the invention.

Referring to the drawings:

FIG. 1 is a front view of a mounting panel carrying several push-button switch units of the sort embodying the present invention;

FIG. 2 is an enlarged sectional view taken substantially along the line 22 in FIG. 1;

FIG. 3 is an exploded view showing several parts of a push-button component of the switch shown in FIG. 2;

FIG. 4 is a perspective view of a housing forming a component of the switch;

FIG. 5 is a perspective view of a switch blade of the sort adapted for assembly as a part of the push-button component comprising the parts shown in FIG. 3;

FIG. 6 is a perspective view of a switch contact of the sort adapted for assembly in the housing component shown in FIG. 4;

FIG. 8 is an enlarged side view of the push-button component shown in FIG. 3;

FIGS. 7, 9 and 10 are sectional views respectively taken substantially along the line 7-7 in FIG. 4; along the line 99 in FIGS. 4 and 7, and along the line 10-10 in FIG. 8;

FIG. 11 is a sectional view taken substantially along the line 11-11 in FIGS. 7 and 9;

FIGS. 12 and are sectional views taken substantially along the line 11-11 in FIGS. 7 and 9 and respectively Showing normally open and normally closed switches, in normal position, while FIGS. 13 and 16, respectively, show the same switches in relatively shifted position, FIGS. 14 and 17 being diagrammatic illustrations of the switches; and

FIGS. 18, 21, 24 and 27 are sectional views taken substantially along the line 99 in FIG. 7, and respectively showing different switching arrangements, each in its normal position, while FIGS. 19, 22, and 28, respectively, show the same structures in relatively shifted position, FIGS. 20, 23, 26, 26a, 29 and 29a being diagrammatic illustrations of the structures.

To illustrate the invention, the drawings show a plurality of push-button switches 21 mounted on a conventional support panel 22. The panel 22 may comprise a plate of mate-rial having substantially uniform thickness and provided with mounting openings 23 peripherally shaped to snugly receive the push-button switches to be mounted. Any suitable or convenient means may be employed for attaching the switches on the panel. For example, each switch may comprise a housing 24 having an outstanding flange or ledge 25, preferably fonmed at its proximal end. Rearwardly of the ledge, the housing may be shaped to extend freely in the mounting opening 23, with the ledge or fiange seating upon the front face of the panel, outwardly of the opening, and the housing may be anchored, in the opening in any convenient manner, for example, as shown in our copending application filed Mar. 13, 1967, under Ser. No. 622,689, the details of which form no part of the invention herein disclosed and claimed.

The housing 24 may conveniently be formed by molding suitable electrical insulating material, such as glass filled nylon, in a forming die. The housing 24 may be and preferably is of square sectional configuration, open at its proximal end, the housing having opposed pairs of side walls 26, 27 and a bottom wall 28, at its distal end. The bottom wall may be formed with a central channel 29 extending therethrough and opening upon the inner and outer faces of the bottom wall. The switch may also comprise a push-button frame 31 axially movable within the housing, between retracted and relatively projected switching positions. The frame 31 may carry one or more switch blades 32 mounted thereon in position to cooperate each with a corresponding pair of preferably silver plated bronze conductor strips 33 mounted in peripherally spaced relationship within the housing, the contact elements or r strips 33, in cooperation with one or more of the frame carried blades, may form one or more switches in the unit.

The push-button frame, like the housing may conveniently be formed by die molding suitable electrical insulating material, such as medium impact ABS (acrylonitrilebutadiene-styrene)polymer. The frame may comprise an integral finger piece 35 projecting outwardly of the housing, at its proximal end, in position for switch actuating operation in response to manual pressure applied thereto in a direction to move the frame into the housing, through its open end, against the contrary bias of a resilient, preferably helical compression spring 37. One end of the spring may be disposed in position engaging the inner face of the bottom wall 28 of the housing, around the opening 29. The spring may extend, in a sleevelike channel or pocket 39 formed in the frame 31, in position concentrically encircling a central, axially extending guide stem 40. The inner end of the stem may be integrally connected with the frame, at the inner end of the pocket or channel 39. The opposite end of the stem may extend outwardly of the open end of the pocket 39 and thence through the bottom opening 29 of the housing, the stem 40 being sized for free sliding movement, snugly in the opening. The spring 37 may thus normally urge the frame 31 toward retracted position, with the finger piece 35 extending outwardly of the open or proximal end of the housing, said position being determined by the engagement of a pair of cooperating limit stops on opposite sides of the switch structure and comprising projections 41, formed preferably one on each of the opposite sides of the frame, at the inner end of the finger piece 31, and longitudinal slots 42 formed in the housing, one in each of its opposite sides 26, in position extending rearwardly from the ledge 25.

The switch contact elements 33 may conveniently comprise strips of thin sheet metal stock having thickness of the order of 0.016 of an inch. While any suitable conducting material may be employed, it is preferable that brass or other reasonably long-wearing material be used. The elements 33 may have length of the order of A of an inch and each may be formed with a butt or mounting end 45 preferably having width of the order of 0.1 of an inch, the opposite or butt remote end 46 of each strip having reduced width of the order of 0.08 of an inch through about onethird of their length, from and outwardly of an inclined shoulder 47 formed on one side of the strip preferably at an angle of the order of forty-five degrees, the opposite or shoulder remote side 48 of each strip preferably being continuously flat from end to end. The butt end 45 of each strip, at its terminal extremity may be formed with an opening 49 to facilitate the connection thereof in external electrical circuitry. An outstanding projection 50 may be formed on each strip, medially between the inclined shoulder 47 and the perforated or butt end of the strip. This projection, on one side, may form a shoulder 51 facing the perforated end of the strip, while, in the opposite direction, the projection may form an outwardly inclined Wedge 53. The opposite side edge 48 of the strip may be formed with a notch 55 spaced from the shoulder 51, toward the perforated end of the strip, a distance of the order of the thickness of the housing end wall 28, which may be formed therethrough with referably rectangular openings 57 sized to snugly receive the butt ends 45 of the contact strips. As a consequence, the strips 33 may be mounted in the housing by insertion thereof, butt ends first through the open proximal end of the housing and thence into and through the strip mounting openings 57. When so mounted the terminal ends of the strips may project outwardly of the bottom of the housing, with the shoulders 51 resting in pockets or seats 59 formed in the inner side of the housing wall 28, to thereby support the strips in mounted position in the housing, with the notches 55 extending in alignment with the outer face of the wall 28. The strips may be anchored, in mounted position in the housing, by twisting the projecting butt ends of the strips, to thereby clinch the notched portions thereof over upon the outer face of the wall 28.

In this connection it will be seen that the openings 57 extend at and inwardly of the housing walls, 26, 27 and that the pockets 59 are formed in the wall 28 at the wall remote edges of the contact mounting openings, the pockets 59 being sized to snugly receive the projections or fingers 50, and to wedgingly engage the inclined outer edge 53 of the finger 50, so that, when the contact strips are assembled in mounted position in the housing, the wedging action of the finger 50 in the pocket will aid in snugly retaining the contact strips in mounted position. The wedge portion 53 of the finger may form a hook 61, as shown, so that a number of strips may be hookingly supported in a suitable assembly jig and thrust in unison into the housing, through its open end, and thus assembled in mounted position in the openings 57.

The contact elements 33 are preferably manufactured in several sizes, A, B and C, which differ in the length of the butt remote portion 46, measured from the shoulder 47. Such lengths may be of the order of nine, eleven and thirteen thirty-seconds of an inch, respectively, for the A, B and C elements. 7

The peripherally disposed contact mounting openings 57 may include four openings spaced apart along each of the opposed housing walls 26, each opening on one side of the housing being in coplanar alignment with a corresponding opening on the opposite side of the housing. The two medial openings 63, on each side of the housing are preferably spaced equally on opposite sides of the medial longitudinal plane which normally bisects the housing walls 26, while the remaining openings 65 are each disposed between a corner of the housing and the nearest adjacent opening 63. A single opening 67 is preferably disposed medially of and normal to each of the opposed housing walls 27, said openings 67 being mutually in coplanar alignment, and each being disposed medially between a pair of corner openings 65.

The push-button frame 31 may be formed with switch blade mounting fingers 69 comprising radial ribs extending longitudinally from the finger piece 35, toward the opposite end of the frame, there being a pair of diametrally opposed ribs 71 in position to extend, respectively, between the pairs of spaced openings 63 on opposite sides of the housing, and a pair of spaced ribs 73 disposed, on each of the opposite sides of the frame, at right angles to the ribs 71, in position so that each pair of ribs 73 may extend on opposite sides of the openings 67, with each rib 73 disposed between an opening 67 and a corresponding corner opening 65. The ends of the fingers, remote from the finger piece 35 are rounded to form semi-cylindrical blade supporting shoulders 75. The opposite sides and rounded end of each blade mounting finger is preferably formed with a shallow switch blade seat 77 extending inwardly of a marginal flange 79.

As shown in FIG. 5, each blade 32 may comprise a preferably silver plated strip of resilient springy sheet metal, such as spring tempered bronze, which preferably may have thickness of the order of 0.006 of an inch. Each blade may have a semi-cylindrical contact engaging shoe portion 81 formed at each of the opposite ends of the strip, each strip being bent to provide legs 83 and 85 mutually inclined at an angle of the order of thirty degrees. At the junction of the legs, the strip may be curved on a radius of the order of that of the semi-cylindrical shoulders 75, to provide a blade seating portion 87. Accordingly, a switch blade 32 may be assembled on any one or more of the blade seats of the frame 31, by rockably mounting the seating portions 87 of the blades upon the semi-cylindrical shoulders 75, with the legs of each blade disposed on opposite sides of the mounting finger on which it is assembled. The assembled blades 32 may be retained in mounted position on the frame 31 by means of a retaining plate 89 preferably of insulating material. The plate 89 may have a central opening sized to snugly receive a collar 90 formed on the frame 31 around the open end of the spring pocket 39 opposite the blade supporting shoulders 75. The plate 89 has a plurality of outwardly extending projections 91 in position to overlay the rocka-bly supported switch blade mounting portions 87 on the blade mounting shoulders 75. The plate 89 may be secured in blade retaining position on the frame 31 by heat pressing the material of the collar 90 over upon the plate 89 as shown at 91, in FIG. 8.

As shown in FIGS. l2, 13, and 16, simple normally open or normally closed switches can be provided by assembling a short contact 33A and a long contact 33C in the pairs of opening 63, and by mounting switch blades 32 on the mounting fingers 71 which extend between said openings. Preferably integral contact covering flanges 93 and 95 are provided in the housing in position overlying the lower portions of the mutually facing sides of the contact elements 33C and 33A. Flange 93 covers the butt portions of the element 33C to about or slightly beyond the shoulder 47, while the flange 95 overlies the element 33A to about midway between the shoulder 47 and the shoulder remote end of the contact element portion 46. As a consequence, the contact shoe portions 81 of a blade may electrically connect with the portions of the contact 6 elements that are exposed upwardly of the flanges 93 and 95.

By disposing the switch blade on the slide 31 in position with the contact shoe 81 of its short arm in engagement with the long contact element 33C, a normally open switch is provided, as shown in FIGS. 12, 13 and 14. This result is obtained because, in the normal, frame-retracted position, shown in FIG. 12, the contact shoe of the long arm 83 of the blade extends in switch open posi tion, beyond the end of and hence disengaged from the short contact element 33A. The contact shoe, however, engages the short contact element 33A, thereby closing the switch, when the frame 31 is in projected position, as shown in FIG. 13, the contact shoe of the short arm of the blade being engaged with the long contact 330 in both positions of the frame.

By assembling the switch blade on the slide 31 in position with the contact shoe 8 1 of its long arm 83 in engagement with the long contact element 330, a normally closed switch is provided. This result is obtained because, in the normal, frame retracted position, shown in FIG. 15, the contact shoe of the short arm 85 of the blade extends in switch closed position engaged and hence electrically connected with the short contact element 33A. The contact shoe, however, engages the flange and is thus, in switch open position disengaged from the short contact element 33A, when the frame is in shifted position, as shown in FIG. 16, the contact shoe of the long arm of the blade being engaged with the long contact element 33C in both frame positions.

By appropriately orienting the switch blades 32 on the blade mounting shoulders, the contact elements 33A and 33C in the pairs of openings 63 on each of the opposite sides of the housing may be constituted either as normally open or normally closed switches. It is also possible to provide normally open or normally closed switches, at will, by mounting contact elements in the corner openings 65 and in the medial openings 67, and by assembling switch blades 32 in appropriately oriented position in the blade seats 75 of the blade mounting fingers 73, which are disposed in the space between the openings 65 and 67. Not only may single normally open or normally closed switches be provided by pairs of contact elements in any or all of the openings 65 and 67, in conjunction with blades 32 in the seats, but various more or less complex switching combinations may be formed by contact elements mounted in the openings 65 and 67 and blades 32 assembled in the blade seats 75, as shown in FIGS. 18 through 29, in which long contact elements 33C are mounted in each of the medial openings 67, while relatively shorter contact elements are assembled in the corner openings 65.

It will be seen that the housing may be formed with contact covering flanges 97, similar to the flanges 93 and 95, disposed in position covering opposite sides of the butt portions 45 of the contact elements 33C, in the openings 67, to about or slightly beyond the shoulder 47. A function of the flanges 97, as is also the case with the flanges 93 and 95, is to prevent accidental engagement of the blades 32 with the butt portions of the contact elements. The housing may also be provided with contact covering portions 99 on each of the opposite sides of contact elements mounted in the corner openings 65, the said covering portions 99 being cut away as at 101 to expose the inwardly facing edges of the butt remote portions 46 of the contact elements in the corner openings, the cutaway portions 101 forming cam shoulders 103 defining the ends of the exposed edges of the contact elements.

It will be appreciated that a normally open or a normally closed switch may be provided by a long contact element 33C in either medial opening 67, in conjunction with a short contact element 33A in either of the openings 65 that are disposed on opposite sides of the medial opening. As shown in FIGS. 18, 19 and 20, however, wherein short contact elements 33A are mounted in each of a pair of corner openings 65 on opposite sides of a medial opening 67, a normally open and a normally closed switch combination may be provided, the same constituting the equivalent of a single pole double throw switch as shown in FIG. 20, by assembling a pair of blades 32 on adjacent push-button fingers 73, in position for operation respectively, between the contact element 33C and each of the elements 33A, the blades being oriented on the blade seating fingers 75, in position such that the long arm of one blade and the short arm of the other are in engagement with the opposed sides of the medially disposed long contact element 33C.

The blade of which the long arm is engaged with the medially disposed contact element forms a normally closed switch, since the long and short arms of the blade respectively engage the long and the short contact elements 33C and 33A, when the blade carrying frame is in retracted position; but the contact shoe of the short arm of the blade engages the cam 103 and becomes disengaged from the contact element 33A as the blade carrying frame reaches its projected position thereby opening the normally closed switch. The blade which has its short arm in engagement with the medial contact element 33C, however, forms a normally open switch, since the contact shoe of its long arm, when the frame 31 is in retracted position, extends in switch open position, beyond the end of its associated short contact element 33A and consequently disengaged therefrom; but the contact shoe of said long arm engages with and rides upon its said associated element 33A and so closes the switch, when the blade carrying frame is projected.

The length of the short contact element 33A is such that the normally open switch, in the FIGS. 18 and 19 embodiment closes after the normally closed switch opens, as the blade carrying frame 31 moves toward its relatively shifted position. By assembling a somewhat longer contact element 333, in the combination providing the normally open switch, in the embodiment shown in the FIGS. 21, and 22, the normally open switch can be made to close prior to the opening of the normally closed switch, thereby providing the switch arrangement shown diagrammatically in FIG. 23.

As shown in FIGS. 24 and 25, switch blades 32 may be assembled on the supporting fingers 73 in position such that the contact shoes of the short arms 85 of both blades engage the opposite sides of the long, centrally mounted contact element 33C, in order to constitute both switches of the combination as normally open switches, in which the contact shoes of the long arms of the switch blades extend beyond the terminal ends of the contact elements 33A and hence are disconnected therefrom, when the blade carrying frame 31 is in normal retracted position, the contact shoes of the long arms of the blades coming into sliding electrical contact with the portions 46 of both contact elements 33A, to thereby close both switches when the push-button frame 31 is moved to its relatively shifted or projected position. The arrangement shown in FIGS. 24 and 25 thus provide a pair of normally open switches that are adapted to close simultaneously, as and when the contact elements of the long arms of the switch blades engage the terminal ends of the portions 46 of the contact elements 33A, as shown in FIG. 26. By substituting a slightly longer contact element 3313 in either of the switch forming combinations, the switch embodying such slightly longer contact elements can be made to close in advance of the other switch of the combination, as depicted in FIG. 26a.

As shown in FIGS. 27 and 28, the switch blades 32 may be assembled on the supporting fingers 73, in position such that the contact shoes of the long arms 83 of both blades engage the opposite sides of the long centrally mounted contact elements 33C, the contact shoes of the short arms of the blades respectively bearing upon the exposed portions 46 of the spaced contact elements 33A, in order to constitute both switches of the combination as normally closed switches, which are adapted to open when the contact shoes of the short arms of the switch blades engage the cam shoulders, 103, when the blade carrying frame reaches its relatively shifted position. The arrangement shown in FIGS. 27 and 28 thus provides a pair of normally closed switches that are adapted to open simultaneously as and when the contact elements of the short arms of the switch blades engage and ride upon the cam shoulders 103, to thus provide a switching combination of the sort depicted in FIG. 29. If it should be desirable to have either of the constituent switches open in advance of the other, one of the blades may be made with a short arm 83 slightly longer than the short arm of the other blade, whereby the switch containing the blade having the slightly elongated short arm will open after the opening of the other switch, thereby providing a switching arrangement of the sort shown in FIG. 29a.

It will be understood, of course, that a switch unit may comprise a housing 24 and frame 31 fitted with a single blade 32 and a pair of switch contact elements 33 to provide a single normally open or normally closed switch in the assembly; or blades 32 and contact elements 33 may be assembled to provide any desired number of separate switch combinations in a single switch unit, up to the capacity of the unit as determined by the number of blade seats, in the slide 31, and the number of contact element mounting openings on seats in the housing.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed comprising preferred embodiments for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. An electrical switch comprising a support frame, plurality of spaced contact elements on the frame, a switch blade carriage having a blade carrying seat movable on the support frame between a normal relatively retracted position and a relatively projected position adjacent said spaced contact elements, a switch blade mounted on said seat in electrical engagement with one of said contact elements, said blade being movable with said carriage in position to selectively engage and disengage another of said contact elements, as the carriage is shifted between its retracted and projected positions, said contact elements being elongated electrical conductors and said blade being a medially bent conductor strip of resilient material having legs extending each in position to move longitudinally of and to slidingly engage a corresponding one of the contact elements, during movement of the carriage between its retracted and projected positions, the medially bent portion of the blade between its legs forming a blade mounting portion and means to retain the blade on said frame with said mounting portion in rocking engagement with said blade seat.

2. An electrical switch comprising a support frame, plurality of spaced contact elements on the frame, a switch blade carriage having a blade carrying seat movable on the support frame between a normal relatively retracted position and a relatively projected position adjacent said spaced contact elements, a switch blade mounted on said seat in electrical engagement with one of said contact elements, said blade being movable with said carriage in position to selectively engage and dis engage another of said contact elements, as the carriage is shifted between its retracted and projected positions, said contact elements being elongated electrical conductors and said blade being a medially bent conductor strip of resilient material having legs extending each in position to move longitudinally of and to slightly engage a corresponding one of the contact elements, during movement of the carriage between its retracted and projected positions, the contact elements being of unequal length and the blade being oriented on its seat in position with one of its arms in engaging contact with the long element and its other arm extending beyond the end of and hence disconnected from the short element, to thereby form an open switch when in normal retracted position, said other arm of the blade being positioned to engage and electrically connect with said short contact element, to thereby close the switch, when in projected position.

3. An electrical switch comprising a support frame, plurality of spaced contact elements ,on the frame, a switch blade carriage having a blade carrying seat movable on the support frame between a normal relatively retracted position and a relatively projected position adjacent said spaced contact elements, a switch blade mounted on said seat in electrical engagement with one of said contact elements, said blade being movable with said carriage in position to selectively engage and disengage another of said contact elements, as the carriage is shifted between its retracted and projected positions, said contact elements being elongated electrical conductors and said blade being a medially bent conductor strip of resilient material having legs extending each in position to move longitudinally of and to slidingly engage a corresponding one of the contact elements, during movement of the carriage between its retracted and projected positions, the arms of the blade being in engagement each with its associated contact element, when in normal retraced condition, to thereby form a normally closed switch structure, and means formed on the support frame in position to disengage one of the blade arms from its associated contact element and hence cause the switch to open when in its projected position.

4. An electrical switch comprising a support frame, plurality of spaced contact elements on the frame, a switch blade carriage having a blade carrying seat movable on the support frame between a normal relatively retracted position and a relatively projected position adjacent said spaced contact elements, a switch blade mounted on said seat in electrical engagement with one of said contact elements, said blade being movable with said carriage in position to selectively engage and dis engage another of said contact elements, as the carriage is shifted between its retracted and projected positions, said contact elements being elongated electrical conductors and said blade being a medially bent conductor strip of resilient material having legs extending each in position to move longitudinally of and to slidingly engage a corresponding one of the contact elements, during movement of the carriage between its retracted and projected positions, the arms of the blade being of unlike length and one contact element being shorter than the other, whereby the switch may be constituted as normally closed or normally open by orienting the blade on its carrying seat in position with its long and short arms in position for cooperative engagement, respectively, with the long and short contact elements, or vice versa.

5. An electrical switch, as set forth in claim 4, wherein the short arm of the blade engages the long contact element in all relatively shifted switching positions, and the long arm of the blade is sized to project beyond the end of the short contact element, in position disconnected therefrom, when the switch is in retracted position, thereby forming a normally open switch structure.

6. An electrical switch, as set forth in claim 4, wherein the long arm of the blade engages the long contact element in all relatively shifted switching positions, and the support frame is formed with a cam in position to engage the short arm of the blade and disconnect it from the short contact element when the switch is in projected position, thereby forming a normally closed switch structure.

7. An electrical switch comprising a support frame, plurality of spaced contact elements on the frame, a switch bladecarriage having a blade carrying seat movable on the support frame between a normal relatively retracted position and a relatively projected position adjacent said spaced contact elements, a switch blade mounted on said seat in electrical engagement with one of said contact elements, said blade being movable with said carriage in position to selectively engage and disengage another of said contact elements, as the carriage is shifted between its retracted and projected positions, the support frame comprising a hollow housing having side and bottom walls and an opening at its proximal end, remote from the bottom wall, said carriage comprising a push-button frame slidingly mounted for longitudinal movement, between retracted and projected positions in the housing, and having a proximal end forming a push-button projecting at said opening, said contact elements comprising elongated electrical conductors extending in parallel spaced relation longitudinally of a side wall of the housing, said elements having ends project-ing outwardly of the distal end of the housing through mounting openings in the bottom wall of the housing, said push-button frame having the blade carrying seat formed at and facing outwardly of its distal end, in position to move between and longitudinally of the spaced contact elements, as the push-button is shifted between its retracted and projected positions, the switch blade comprising a strip of electrical conducting material having ends extending oppositely from said seat in position for sliding engagement with said contact elements.

8. An electrical switch, as set forth in claim 7, wherein the push-button frame is formed with a longitudinal r-ib in position extending between the contact elements, said rib having an end providing a saddle for seating the blade at the distal end of the push-button frame, the blade being medially bent to form a saddle engaging portion and spaced legs extending from said saddle on opposite sides of said rib in position for sliding engagement with said contact elements.

9. An electrical switch, as set forth in claim 7, including a compression spring seated on the bottom wall of the housing and bearing upon the pushbutton frame to normally urge it in the direction of the proximal end of the housing, and interengaging stop means on the push-button frame and the housing for limiting spring urged relative movement when the push-button frame is in its normal retracted position in the housing.

10. An electrical switch, as set forth in claim 9, wherein said stop means comprises a projection on the pushbutton frame, disposed adjacent and inwardly of its proximal end, and a slot, formed in a side wall of the housing and providing a shoulder, disposed inwardly of the proximal end of the housing and facing toward the distal end thereof, in position forming an abutment for engagement by said projection, when the push button frame is in its normal retracted position in the housing, the resilience of the side walls of the housing, at its proximal end opening permitting said walls to bulge outwardly, at said slot, to permit the projection to snap into interfitting engagement in the slot, upon insertion of the push-button frame through said opening.

11. An elecrical switch, as set forth in claim 7, wherein the push-button frame is formed with a -sleeve-like pocket, opening at its distal, a central guide stem having an end extending out of the pocket, at the distal end of he pushbutton frame, in position to guidingly slide in a central perforation formed in the bottom wall of the housing, and a helical spring concentrically encircling said stem in said pocket, said spring bearing, at one end, upon the bottom of the pocket and, at its other end, upon the bottom wall of the housing.

12. An electrcal switch comprising a support frame, plurality of spaced contact elements on the frame, a switch blade carriage having a blade carrying seat movable on the support frame between a normal relatively retracted position and a relatively projected position adjacent said spaced contact elements, a switch blade mounted on said seat in electrical engagement with one of said contact elements, said blade being movable with said carriage in position to selectively engage and disengage another of said contact elements, as the carriage is shifted between its retracted and projected positions, the contact elements comprising a centrally disposed relatively long element and a pair of relatively short elements disposed laterally on opposite sides of and spaced from the centrally disposed element, the switch blade carriage having a pair of blade carrying seats in position movable on opposite sides of the central contact element and between it and the laterally disposed elements, and a switch blade mounted on each of said seats in position to slidingly engage the central element, each of said blades being in position to slidingly engage a corresponding one of the laterally disposed elements.

13. An electrical switch, as set forth in claim 12, wherein each of said switch blades comprises a medially bent conductor strip of resilient material having legs of unequal length for engagement with said contact elements, the blades being mounted on the blade carriage in position with the long leg of one blade and the short leg of the other blade in sliding engagement with the centrally mounted contact element.

14. An electrical switch, as set forth in claim 13, wherein the short leg of the one blade slidingly engages one of said short contact elements, the long leg of the other blade extending beyond the end of the other short element, when the blade carriage is in normal retracted position, whereby the long arm of said other blade may engage its associated short contact element, when the blade carriage is in projected position, and cam means on the support frame for disengaging the short leg of said one blade from its associated short contact element, when the blade carriage is in projected position, thereby constituting the switching arrangement as pair of switches, one of which is normally open, the other being normally closed.

15. An electrical switch, as set forth in claim 14, wherein the length of the blade arms, the length of one of the 40 short contact elements and the relative position of the blade lifting cam, longitudinally of its associated short contact element, are such as to cause the normally closed switch to open prior to the closure of the normally open switch.

16. An electrical switch, as set forth in claim 14, wherein the length of the blade arms, the length of one of the short contact elemens and the relative position of the blade lifing cam, longitudinally of its associated short contact element, are such as to cause the normally open switch to close prior to the opening of the normally closed switch.

17. An electrical switch, as set forth in claim 12, wherein the blades are oriented on the blade carriage with the short arms of both blades in sliding engagement with the medial contact element, while the long arms of the blades project beyond the ends of the short elements, when the blade carriage is in its normal retracted position, said long arms becoming engaged with said short contact elements, when the carriage is in its projected position, to thereby constitute both switches as normally open.

18. An elecrical switch, as set forth in claim 12, wherein the blades are oriented on the blade carriage with the long arms of both blades in sliding engagement with the medial contact element, while the short arms of the blades are in engagement with the short contact elements, when the blade carriage is in its normal retracted position, and cam means on the support frame in position to engage and lift the short arms of both blades from contact with said short contact elements, when he carriage is in is projected position.

References Cited UNITED STATES PATENTS 1,295,777 2/1919 McGrath ZOO-16 2,594,644 4/1952 Hansen 200l6 3,104,300 9/1963 Hutt 200-159 FOREIGN PATENTS 294,094 4/ 1965 Netherlands.

ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner. 

